When tempering martensite:

a. the chemical covalence rules that the structure originally represents
are no longer represented
b. the atoms of the alloy elements attract the carbon atoms (correct)
c. the atoms of the alloy elements attract each other
d. the carbon atoms form large areas of carbon by self-precipitation

This is a very subtle question. c could also be considered correct, but b is better because it emphasizes the formation of alloy carbides during tempering. I am unsure of the intent in answer a?

Which of the following does NOT control the position of the TTT curve?

a. alloy content
b. heat treatment (correct)
c. AUS grain size
d. per cent carbon

Which of the following is NOT a class of stainless steel?

a. pearlitic (correct)
b. austenitic
c. ferritic
d. martensitic

What do Jominy curves measure?

a. w/o carbon
b. hardenability (correct)
c. amount of pearlite/martensite formation
d. austenitizing temperatures
e. amount of ferrite formation

One way to increase hardenability is to add alloy elements; which of these alloying elements does not latch onto C atoms to effect this increase?

a. V
b. W
c. Cr
d. Mo
e. All of the above
f. None of the above (correct: Si and Ni would not)

Which of the following is not used as a quenching medium?

a. air
b. oil
c. water
d. brine
e. all of the above are used (correct ­ in fact, anything could be used, but usually some type of fluid is employed)

Which is not a way to increase the hardenability of a steel:

a. increase carbon content
b. move TTT curves by decreasing the amount of alloying elements present (correct - alloy element content must be increased)
c. increase quenching rate (also correct ­ hardenability is an inherent characteristic of a steel)
d. increase the size of AUS grain size